After putting up with the loud pop again whenever I used the coarse switch I took the amp home and re-flowed all the in and out joints, to no avail. (The fact that was is in both channels and all positions made me think that unless it was the ground lead it wasn't a soldering issue, but I wanted to cover the bases.)
I again sprayed and swabbed the switch contacts, above and below the deck = Dirty, oily looking swabs and silent switching.
As I posted earlier, a total of 6 switches in 3 amps, all installed by me and this is the only one that has given me any problem. The thought of replacing the pricey switch (if available) is not appealing so again any insight would be appreciated. Paul(s)? Doc?
Thanks,
Karl